80c is a perfectly reasonable temperature for a busy PC. If you want to simulate a higher load, you can do so using XTU, as Leonardo has suggested.

Desktopprocessors publish a temperature threshold, called Tcontrol, which indicates the upper limit for safe operation. By this, I mean that your processor can operate at this threshold constantly, even for its full warranted lifetime, without suffering any thermal degradation. It is ok for temperatures to go above the Tcontrol threshold for brief intervals (spikes), but sustained operation above this threshold is not recommended. While temperatures are above the Tcontrol threshold, it is strongly recommended that your processor cooling fans/pumps/blowers be operating at full speed (100% duty cycle).

You can determine what your processor's Tcontrol threshold is by reading the contents of the IA32 Temperature TargetModel-Specific Register (MSR) (address 0x01A2). Bits 16-23 specify the processor's Maximum Junction Temperature (Tjmax), which is the temperature above which throttling occurs, and bits 8-15 specify the Tcontrol Offset. Subtract the Tcontrol Offsetfrom the Tjmaxvalue to determine the Tcontrolthreshold. There are many freeware programs that you can use to display the contents of MSRs (I use one called RWEverything).